general editors Michael Orme, Susanna Graham-Jones
Penguin Group, 1989
Buku Referensi
French, F. G.
Oxford University Press, 1947
Buku Teks
Holdsworth, Jacqueline
McGraw-Hill, 1994
Buku Teks
Clinard, Marshall B. (Marshall Barron)
The Tree Press, 1966
Buku Teks
Kurtz, Linda Farris
Sage Publications, 1997
Buku Teks